Oil discharges overboard must be recorded in which log?

• A. Cargo record book
• B. Deck log
• C. Oil record book
• D. Engine log

Answer: (C)

Oil discharges overboard are recorded in the Oil Record Book because this log is the official MARPOL record for all oil-related operations on board. It captures discharges of oily mixtures, the processing and discharge of oily water, tank cleaning, and related oil handling activities, along with the time, position, method, and amount involved, all signed by the officer in charge. Keeping this record creates a traceable, auditable record that regulators and port state control can review to ensure compliance and protect the marine environment.

Other logs serve different purposes: the deck log documents navigation and voyage events, the engine log tracks engine-related operations and fuel/oil use, and the cargo record book tracks cargo movements. None of these are the formal repository for oil discharge records. For ships carrying oil cargo, the Oil Record Book may include parts covering cargo residues and tank cleaning, but it remains the official log for oil discharge activities.